Method of and apparatus for combined optical and sonar detection and recording of objects

Abstract

This disclosure is concerned with problems of energy conservation and more effective utilization at desired critical times only in, for example, sonar-triggered underwater elapsed time strobe photography of objects or scenes or in applications having similar problems; accomplishing such and other ends by restricting optical and sonar monitoring to relatively low periodicity intervals until the desired object has come within range, whereupon the apparatus automatically changes mode to take rapid successive strobe photographs or other records supplemented by contemporaneous sonar recording.

What is claimed is: 
     
       1. A method of combined optical and acoustical recording, that comprises, repetitively activating an optical device and thereby periodically optically monitoring an underwater sector and recording the scenes therein at the times of said monitoring; acoustically monitoring said sector at least at said times and recording the monitored acoustical information in said sector; analyzing the acoustical information to determine if and when a predetermined acoustical pattern has been monitored; and, upon detecting the advent of such monitored predetermined pattern, changing the periodicity of said activating for so long as said acoustical pattern continues to be monitored. 
     
     
       2. A method as claimed in claim 1 and in which the said periodicity is changed by increasing the same. 
     
     
       3. A method as claimed in claim 2 comprising, during the increased periodicity of optical monitoring, substantially continually effecting acoustical monitoring. 
     
     
       4. A method as claimed in claim 1 and in which the optical monitoring comprises periodically transmitting flashes of light within said sector to reflect from objects therein. 
     
     
       5. A method as claimed in claim 4 and in which the acoustical monitoring comprises periodically transmitting acoustical sonar impulses within said sector to reflect from objects therein. 
     
     
       6. A method as claimed in claim 5 and in which the acoustical recording comprises effecting recording for short time periods associated with the moments of periodic light flashing. 
     
     
       7. A method as claimed in claim 5 comprising substantially continually recording sonar information during the increased period of light flashing optical monitoring corresponding to continued sonar detection of the predetermined acoustical pattern. 
     
     
       8. A method as claimed in claim 7 and in which said analyzing comprises determining whether said acoustical pattern is a sonar echo pattern of predetermined characteristics within predetermined ranges. 
     
     
       9. A method of combined optical and acoustical monitoring, that comprises, repetitively activating an optical device and thereby optically monitoring a sector and recording scenes therein at desired sampling times; acoustically monitoring said sector at least at said times; analyzing the acoustical information to determine if and when a predetermined acoustical pattern has been monitored; and, upon detecting the advent of such monitored predetermined pattern, increasing the rate of said repetitive activating to effect rapid periodic optical recording within said sector. 
     
     
       10. A method as claimed in claim 9 and in which said rapid optical recording is accompanied by corresponding acoustical recording of the acoustically monitored information in said sector. 
     
     
       11. A method as claimed in claim 9 and in which said optical monitoring and recording is effected by strobe light flashes. 
     
     
       12. A method as claimed in claim 9 and in which the acoustical monitoring is effected by sonar ranging. 
     
     
       13. A method of simultaneous monitoring and recording with the aid of two different types of energy of widely different wavelengths and properties, that comprises, repetitively activating an optical device and thereby periodically monitoring a sector with one type of energy and recording the received scenes therein at the times of said monitoring; monitoring said sector at least substantially at said times with a second type of energy and recording the monitored information therefrom; analyzing said information to determine if and when a predetermined pattern has been monitored; and, upon detecting the advent of such monitored predetermined pattern, changing the repetitive rate of said activating and thereby changing the periodicity of the monitoring and recording by said one type of energy for so long as said pattern continues to be monitored. 
     
     
       14. A method as claimed in claim 13 and in which said monitoring and recording are performed with the aid of said one type of energy that is of wavelength much smaller than that of said second type of energy. 
     
     
       15. A method as claimed in claim 13 and in which the recording of the second type of energy comprises recording at the times of the first-named periodic monitoring by the said one type of energy; and, upon the advent of the predetermined pattern as monitored by the second type of energy, the recording of the second type of energy at the same times as the changed periodicity of the recording by the first type of energy. 
     
     
       16. A method as claimed in claim 15 and in which the monitoring and recording are performed with the aid of said first type of energy that is light energy, visible or invisible, and the second type of energy that is acoustical, audible or ultrasonic. 
     
     
       17. A method as claimed in claim 15 and in which said changing periodicity comprises increasing periodicity. 
     
     
       18. A method as claimed in claim 15 and in which the monitoring by the second type of energy comprises continually monitoring. 
     
     
       19. A method as claimed in claim 15 and in which the monitoring by the second type of energy comprises periodically monitoring. 
     
     
       20. Combined optical and sonar apparatus comprising a camera provided with means for periodically activating the same to record scenes in a predetermined sector; sonar means for contemporaneously probing said sector; means for analyzing the received sonar signals from said sector and means responsive to the detection of a predetermined acoustical pattern in the received sonar signals for thereupon changing the periodicity of the activation of the camera. 
     
     
       21. Apparatus as claimed in claim 20 and in which said changing means comprises means for maintaining the periodicity of camera activation changed for so long as the said predetermined acoustical pattern is received by the sonar means. 
     
     
       22. Apparatus as claimed in claim 20 and in which the said means for changing the periodicity of the camera activation comprises means for increasing periodicity. 
     
     
       23. Apparatus as claimed in claim 22 and in which means is provided for recording the received sonar signals during said increase in periodicity of the camera activation. 
     
     
       24. Apparatus as claimed in claim 20 and in which said camera comprises strobe means operable to effect the periodic activation. 
     
     
       25. Apparatus as claimed in claim 24 and in which means is provided for recording the received sonar signals at the times of the periodic strobe means flashing. 
     
     
       26. Apparatus as claimed in claim 24 and in which the means for changing comprises means for increasing the periodicity of the camera and the strobe means. 
     
     
       27. Apparatus as claimed in claim 26 and in which means is provided for recording said received sonar signals during the increased periodicity activation of said camera and its strobe means. 
     
     
       28. Apparatus as claimed in claim 20 comprises means for continually operating the sonar means. 
     
     
       29. Apparatus as claimed in claim 20 comprising means for periodically operating the sonar means.